I previously posted a blog entry discussing the revolutionary new polymer made from corn resin, known as polylactic acid, or PLA. Since then we have started selling PLA reusable water bottles with filters at The Greater Green, creating quite a buzz of both excitement and apprehension. Over the last few weeks I have learned quite a bit about plastics, the huge agribusiness of corn, and the concerns of many as we search for a safer, cleaner, more biodegradable alternative to the traditional plastics. I decided it was time to write another post, revealing what I have learned, some of which supports the propagation of this new corn resin plastic, and some of which warns us to stop and take a closer look at what is going on.
When I first heard of this new corn plastic, I was incredibly optimistic. There is no doubt that we have a plastics crisis on our hands. In my post "Eternal Wasteland: The Problem of Plastics", I talk about the North Pacific Gyre, an area in the Pacific Ocean about the size of Texas, that has become covered with floating plastic debris. Approximately 250 billion pounds of plastic pellets are being produced each year, and they are not going anywhere- at least not for thousands of years. So when I heard that a new polymer made from corn resin was now available in the form of mugs, cups, bags, and other consumables traditionally made from petroleum-based polymers, it is easy to see where the optimism came from. I even read the proclamation "Made from 100% US-grown corn" with waves of approval. Supporting our farmers, too? What more could we ask for?
Then the comments started coming in, and I realized that I had not been looking at the big picture. Don't get me wrong, by the end of this post, I will still be supporting corn-resin PLA plastics and we will still be selling our PLA water bottles at The Greater Green (which we would not do if we did not believe that they are a significant improvement over PET bottles). But I think it is important that we know this new plastic does come with a price, and if we take a stand early-on, we may be able to turn this new industry into one that truly improves our world in so many ways.
The big problem is that the corn industry is an "agribusiness": corn has become a commodity, and is grown on such a massive scale by huge commercial farms with little regard for the environment. The industry grows primarily GMO corn- that is, Genetically Modified Organisms. Many people have expressed concern over genetically altering produce in irreversible ways, and the unforeseen consequences that may arise down the road. Additionally, corn is one of the most pesticide- and fertilizer-intensive crops, sending billions of pounds of toxins into our waterways, our rivers and lakes and ponds, wreaking havoc on those ecosystems and on the delicate balances that exist within. Fish, birds, even humans, are the victims of this chemical run-off. The once-rich soil of many agricultural regions is now barely able to support growth without heavy fertilizers. We know that crop diversification, which exists on many small, organic farms, is the natural way to keep soil and land healthy and productive. The millions of pounds of corn grown for PLA production are not organic, and this is a major problem.
I decided to look into the company that is the major producer of PLA plastics, NatureWorks LLC. They began production in 2001, when this corporation was formed as a joint effort between Cargill here in the US, and Teijin in Japan. Since their incorporation, they have made some steady improvements in terms of eco-responsibility. NatureWorks now offsets 89% of its energy consumption through the purchase of wind power renewable energy certificates. That makes them the 19th largest carbon offsetter in the country. They have improved the energy efficiency of their PLA production each year, resulting in significant reductions in terms of pollution emitted and energy consumed during the entire life cycle, from "cradle to polymer", of PLA plastics as compared to PET plastics (. Contrary to what I previously thought, these numbers do take into consideration the growth cycle of corn and the energy consumed therein .
According to NatureWorks' website, they source both GMO and non-GMO corn for use in their production facility in Nebraska: "...the corn from which the dextrose is made is sourced from producers within a 30-mile radius of Blair, NE. The corn used to make the dextrose is a mixed stream of non-GMO and GMO corn grown in the area. During the manufacture of PLA, the multiple-stage processing and high heat used to create the polymer removes all traces of genetic material." Unfortunately, such a disclaimer sounds as if they are shrugging off their responsibility toward environmental stewardship while trying to sound like they are doing something. I have already had a number of people tell me they will not support PLA plastics until they are made from GMO-free and organically-grown corn. The question remains: is NatureWorks just another profit-hungry corporate monstrosity, with no regard for the negative environmental impacts of the corn monoculture currently dominated agriculture now? Or will they be a leader in the movement toward a more sustainable and environmentally-responsible economy, and require their corn to be grown at the very least GMO-free, and hopefully, also organically?
As I said in the beginning, I still believe that PLA plastics are a step in the right direction. They may not be the final answer to an environmental plastic crisis, but I believe this new industry will continue to improve. In an ideal world, we would not be consuming so much plastic, or none at all, but right now that is just not going to happen. A quick tour around the average American house will prove that plastics are everywhere. Right now we need to pressure NatureWorks into sourcing non-GMO and organic corn. If consumers demand this of PLA, then we can turn this young industry into a truly beneficial one.
Although PLA is interesting, its use for plastic bottles is problematic. The PLA bottles mixed into the PET bottle recycling stream contaminates that process. The 24% recycle rate for PET plastic bottles is in jeopardy due to this contamination. Since no recycling collection or reclamition process has been developed for PLA bottles, they will be landfilled, not composted.
Anaerobic decomposition of PLA creates methane gas, a worse green house gas than CO2.
So aside from the food-or-fuel crop use issues, there are also end-of-life issues to be worked out for PLA.
Currently a lot of recycled PET is shipped to China for reuse in products, so it's profitable to do curb-side collection of PET. There is little profit composting PLA into soil, so curb-side recycling is unlikely to develop.
Posted by: SteveW | April 26, 2008 at 04:31 PM
There are a lot of problems with PLA - If we made all of the plastic disposable items used in the world every year, it would take one hundred million tons of corn to make it. That would lead to mass starvation in the third world, as that represents at least 10% of the world's grain supply. Also, in landfills, PLA exudes methane when it decomposes-and methane is a potent greenhouse gas. It also takes a huge amount of diesel to grow, fertilize, ship, and process this corn. As a practical matter, it is also not recyclable. The alternative? Oxo-biodegradable plastics. See http://biogreenproducts.biz for full information. -Tim Dunn
Posted by: Tim Dunn | January 22, 2009 at 06:51 PM